projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | /* This is a module which is used for setting the TOS field of a packet. */ |
| 2 | ||
| 3 | /* (C) 1999-2001 Paul `Rusty' Russell | |
| 4 | * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> | |
| 5 | * | |
| 6 | * This program is free software; you can redistribute it and/or modify | |
| 7 | * it under the terms of the GNU General Public License version 2 as | |
| 8 | * published by the Free Software Foundation. | |
| 9 | */ | |
| 10 | ||
| 11 | #include <linux/module.h> | |
| 12 | #include <linux/skbuff.h> | |
| 13 | #include <linux/ip.h> | |
| 14 | #include <net/checksum.h> | |
| 15 | ||
| 16 | #include <linux/netfilter_ipv4/ip_tables.h> | |
| 17 | #include <linux/netfilter_ipv4/ipt_TOS.h> | |
| 18 | ||
| 19 | MODULE_LICENSE("GPL"); | |
| 20 | MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); | |
| 21 | MODULE_DESCRIPTION("iptables TOS mangling module"); | |
| 22 | ||
| 23 | static unsigned int | |
| 24 | target(struct sk_buff **pskb, | |
| 25 | const struct net_device *in, | |
| 26 | const struct net_device *out, | |
| 27 | unsigned int hooknum, | |
| 28 | const void *targinfo, | |
| 29 | void *userinfo) | |
| 30 | { | |
| 31 | const struct ipt_tos_target_info *tosinfo = targinfo; | |
| 32 | ||
| 33 | if (((*pskb)->nh.iph->tos & IPTOS_TOS_MASK) != tosinfo->tos) { | |
| 34 | u_int16_t diffs[2]; | |
| 35 | ||
| 089af26c | 36 | if (!skb_make_writable(pskb, sizeof(struct iphdr))) |
| 1da177e4 LT |
37 | return NF_DROP; |
| 38 | ||
| 39 | diffs[0] = htons((*pskb)->nh.iph->tos) ^ 0xFFFF; | |
| 40 | (*pskb)->nh.iph->tos | |
| 41 | = ((*pskb)->nh.iph->tos & IPTOS_PREC_MASK) | |
| 42 | | tosinfo->tos; | |
| 43 | diffs[1] = htons((*pskb)->nh.iph->tos); | |
| 44 | (*pskb)->nh.iph->check | |
| 45 | = csum_fold(csum_partial((char *)diffs, | |
| 46 | sizeof(diffs), | |
| 47 | (*pskb)->nh.iph->check | |
| 48 | ^0xFFFF)); | |
| 1da177e4 LT |
49 | } |
| 50 | return IPT_CONTINUE; | |
| 51 | } | |
| 52 | ||
| 53 | static int | |
| 54 | checkentry(const char *tablename, | |
| 55 | const struct ipt_entry *e, | |
| 56 | void *targinfo, | |
| 57 | unsigned int targinfosize, | |
| 58 | unsigned int hook_mask) | |
| 59 | { | |
| 60 | const u_int8_t tos = ((struct ipt_tos_target_info *)targinfo)->tos; | |
| 61 | ||
| 62 | if (targinfosize != IPT_ALIGN(sizeof(struct ipt_tos_target_info))) { | |
| 63 | printk(KERN_WARNING "TOS: targinfosize %u != %Zu\n", | |
| 64 | targinfosize, | |
| 65 | IPT_ALIGN(sizeof(struct ipt_tos_target_info))); | |
| 66 | return 0; | |
| 67 | } | |
| 68 | ||
| 69 | if (strcmp(tablename, "mangle") != 0) { | |
| 70 | printk(KERN_WARNING "TOS: can only be called from \"mangle\" table, not \"%s\"\n", tablename); | |
| 71 | return 0; | |
| 72 | } | |
| 73 | ||
| 74 | if (tos != IPTOS_LOWDELAY | |
| 75 | && tos != IPTOS_THROUGHPUT | |
| 76 | && tos != IPTOS_RELIABILITY | |
| 77 | && tos != IPTOS_MINCOST | |
| 78 | && tos != IPTOS_NORMALSVC) { | |
| 79 | printk(KERN_WARNING "TOS: bad tos value %#x\n", tos); | |
| 80 | return 0; | |
| 81 | } | |
| 82 | ||
| 83 | return 1; | |
| 84 | } | |
| 85 | ||
| 86 | static struct ipt_target ipt_tos_reg = { | |
| 87 | .name = "TOS", | |
| 88 | .target = target, | |
| 89 | .checkentry = checkentry, | |
| 90 | .me = THIS_MODULE, | |
| 91 | }; | |
| 92 | ||
| 93 | static int __init init(void) | |
| 94 | { | |
| 95 | return ipt_register_target(&ipt_tos_reg); | |
| 96 | } | |
| 97 | ||
| 98 | static void __exit fini(void) | |
| 99 | { | |
| 100 | ipt_unregister_target(&ipt_tos_reg); | |
| 101 | } | |
| 102 | ||
| 103 | module_init(init); | |
| 104 | module_exit(fini); |